Recirculating paint system having an improved push to connect fluid coupling assembly

ABSTRACT

A recirculating paint supply system having a supply conduit, a return conduit and a push to connect fluid coupling assembly. The supply conduit supplies a liquid coating composition received from a supply to a spray nozzle. The return conduit returns the excess liquid coating composition supplied to the spray nozzle to the supply. The push to connect fluid coupling assembly receives an end portion of at least one of the supply conduit and the return conduit. The push to connect fluid coupling assembly includes a connector housing defining a bore having a first annular groove to retain an annular lock ring positioned within the groove. The lock ring is operable to grip and engage the outer periphery of the conduit to securably retain the conduit in the connector housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of prior application U.S. Ser. No.09/228,200, filed Jan. 11, 1999, now U.S. Pat. No. 6,164,558, issuedDec. 26, 2000, which is a continuation of U.S. Ser. No. 08/831,622,filed Apr. 9, 1997, now U.S. Pat. No. 5,857,622, issued Jan. 12, 1999,which is a continuation of U.S. Ser. No. 08/659,635, filed Jun. 6, 1996,now U.S. Pat. No. 5,772,116, issued Jun. 30, 1998, which is acontinuation-in-part application of U.S. Ser. No. 08/503,979, filed Jul.19, 1995, now U.S. Pat. No, 5,823,438, issued Oct. 20, 1998, which is acontinuation-in-part application of U.S. Ser. No. 08/161,825, filed Dec.2, 1993, now U.S. Pat. No. 5,501,397, issued Mar. 26, 1996.

BACKGROUND OF THE INVENTION

This invention relates to a paint system including a flexible conduit orhose arrangement to supply a liquid coating composition from a paintsupply system to a spray gun. More particularly, this invention relatesto an improved spray gun for the paint system.

As those familiar with the prior art will appreciate, in previous paintsupply systems, a base coat of paint is applied at a first station andthen the article, such as an automobile body, is conveyed to a newstation where a clear coat paint is applied, the clear coat paint addingthe feeling of depth to the paint. The ability to apply a clear coat anda base coat at the same time would provide a dramatic reduction in thecost of painting the car in the sense that half of the spray boothscould be eliminated or deactivated and therefore half of the equipmentand half of the manpower could be eliminated from the paintingoperation.

Additionally, the modern factory is typically spread out and paintbooths are not localized in one area or arranged so as to be parallel toone another. As a result, the use of a series connection between paintbooths requires extensive tubing, particularly when the paint must besupplied to opposite sides of each booth. Accordingly, it would bedesirable to minimize the number of lines needed to supply paint in apaint system and the cost associated with these lines.

A continuing problem associated with the spray application of liquidpaints is the presence of foreign particulate matter in the liquid paintsupply which causes imperfections on the surfaces of the article beingspray painted, frequently necessitating a refinishing or repaintingthereof. Such foreign particulate matter, sometimes referred to as“seeds,” or “strings,” or “snotters” are formed in many instances as aresult of an agglomeration of the paint constituents during standing orrecirculation of the liquid paint necessitating removal prior todischarge through the spray nozzle. The foregoing problem isparticularly pronounced in recirculating type liquid paint systems,although they are present in direct line systems as well.

Recirculating paint supply systems conventionally comprise a mixing tankequipped with suitable agitation for maintaining the liquid coatingcomposition uniformly mixed and a pump for transferring the liquidcoating composition under a desired pressure to a manually manipulablesupply conduit connected to the spray nozzle. A suitable return hose isprovided for returning the excess quantity of paint back to the mixingtank for recirculation and to keep the paint in suspension. Typical ofsuch a system is the recirculating paint supply system shown in U.S.Pat. No. 5,060,861, the specification of which is incorporated herein byreference. In this paint supply system, the supply and return hoses areinterconnected by suitable fluid fittings so as to form a single conduithaving coaxial passages for supplying and returning the liquidcomposition.

This and like paint systems typically will utilize many differentfittings, connectors and coupling arrangements to complete the necessaryfluid interconnections. Such fittings are often generally made of metalwhich can result in the conduit being relatively heavy. However, thepaint supply hoses or unitized fluid conduit, and the associated fluidfittings, should be as light as possible to reduce operator fatigue andenable the operator to manipulate the position of the spray gun.

Moreover, conventional spray guns are also generally made of metal whichresults in the spray gun, including the fittings to be relatively heavy.This weight may cause operator fatigue or ailments based upon thecontinuous and repetitive use of the heavy spray gun, which typicallyweighs about 22 ounces. Still further, as the work day draws on, thisfatigue increases which may cause an appreciable decrease in finishquality of the object being coated. This decreased quality generallyoccurs because the operator may angle the spray delivered from the spraygun as opposed to maintaining the spray substantially perpendicular tothe object which is desired.

Seals and filters are also included in the paint supply line to seal theinterconnections as well as to remove particulate matter from the paintbeing provided to the spray gun. In spite of the seals and filters,foreign matter can still be present. For example, the quick connectorsused for the spray gun tend to create spit at the quick disconnect upondisconnecting which is generally not noticeable but, when dry, willcause leakage and contamination to occur. Further, to prevent leakage,it is known to cover the threaded sections of fluid fittings with pipedope and then assemble the fittings. While this arrangement works wellin many fluid sealing applications, it has several disadvantages. First,a pipe fitter must be called to assemble or disassemble the unit, whichcan be an inconvenience. Further, exposed threads create voids in thejoint between the components which causes paint to accumulate andgenerates paint particles (dirt, etc.) that will be sent downstream andend up on the car, resulting in the need to rebuff and/or repaint thecar.

Various flow control devices or paint restrictors are also used withpaint supply systems. In many cases such prior art constructions havebeen handicapped by their tendency to become plugged over periods ofuse, necessitating frequent replacement and/or downtime to permitcleaning to restore them to proper operating conditions. The build up ofdeposits in such flow regulators cause a progressive decrease in thepressure of the liquid coating composition supplied to the spray nozzle,thereby resulting in variations in the quality and thickness of thecoating, thus detracting from their use.

Moreover, a flow control device must include an element that movesrelative to its valve body in order to change the flow rate. Forexample, a conventional ball valve has a rotatable ball member throughwhich fluid can flow and seal portions positioned at the opposingupstream and downstream faces of the ball to inhibit flow therearound.Extended use of the valve member in one flow position can result inpaint coagulating in voids formed around the seal portions. When theball member is rotated, paint portions can break loose, thus detractingits use. Paint flakes, particles and dirt can result from the mating offluid connector members, notwithstanding a seal being positioned toprevent flow around mated portions.

Accordingly, it would be desirable to limit or replace the use ofthreaded fittings with compression fittings, or those that use onlypressure, thereby eliminating voids which tend to cause the paint toaccumulate.

Moreover, it would also be desirable to reduce the weight of theconventional spray gun and fittings, thereby reducing operator fatigueand increasing finish quality.

SUMMARY OF THE INVENTION

The benefits and advantages of the present invention are obtained in arecirculating paint supply system that has a substantially flexiblerecirculating fluid conduit connected at one end to a spray gun and atits other end to supply and return lines of a paint supply.

To selectively connect and disconnect the supply and return lines of thepaint system to the supply and return hoses of the recirculatingconduit, a series of ball valves are interconnected to form an H-shapedfluid connector assembly. According to an exemplary embodiment of thisinvention, a funnel shaped seal is sandwiched between matingfrustoconical surfaces of the interconnected ends of the valves wherebyto form a compression seal. Alternatively, the interconnected ends ofthe valves may be coupled by the use of flare fittings using matingconical surfaces. Additionally, the interior surfaces of the valveswhich contact the paint composition are comprised of stainless steel orother suitable metal, that is resistant to attack by the paint.

According to a preferred embodiment of the paint system of the presentinvention, the H-shaped fluid connector assembly includes a connectingmechanism having an annular member pivotably mounted to each handle ofthe ball valves. When the annular member is moved with a clockwiseforce, each handle on each ball valve is simultaneously moved tosimultaneously open and close the ball valves. This allows therecirculating conduit to be quickly checked for pressure differential orloss.

According to a preferred embodiment of the paint system of the presentinvention, the discharge end of the recirculating fluid conduit has afluid fitting secured thereto. In an exemplary embodiment, helicalconvolutions having a predetermined pitch width extend radially outwardfrom the fitting, and a guard for protecting the outer periphery of theconduit and providing strain relief to conduit is secured to the helicalconvolutions. The fluid fitting includes a rotatable coupling nut, andthe guard includes a wire helically coiled to form a generallycylindrical member that encircles an axial portion of the conduit andextends axially away from the fitting. A portion of the wire helix hasthe same predetermined pitch width as and threadably engages theconvolutions, coupling rotation of the nut tending to tighten theengagement of the coil with the convolutions.

According to another preferred embodiment of the paint system of thepresent invention, particularly applicable for the manual sprayapplication of liquid coating compositions, a quick disconnect connectorassembly is provided to enable the rapid connection and disconnection ofthe fluid conduit and prevent unwanted spit of paint during theconnection or disconnection to the spray gun. The quick disconnectconnector assembly comprises a valve body having a bore, a tubular fluidconduit having a stem which is inserted into the bore, a seal elementhaving a passage positioned in the bore, and a first closure membernormally engaged with the seal for sealing the passage and movable fromsealed engagement by the inward insertion of the stem. The stem and theseal passage are dimensioned such that the forward end portion of thestem is adapted to establish sealing engagement with the wall of theseal passage both when the stem has been partially inserted into thepassage but prior to engaging the first closure member, during whichtime no flow is permitted through the connector assembly, and also whenfully inserted into the passage, whereby to move the first closuremember from its flow preventing engagement with the seal.

According to another preferred embodiment of the quick disconnect fluidconnector assembly of the present invention, the stem includes a secondclosure member to seal the stem when it is removed from the bore of thevalve body. When the stem is inserted into the bore and the firstclosure member is moved from engagement with the seal, the pressure andfluid in the fluid conduit causes the second closure member to be movedto enable the flow of fluid through the stem. When the stem is removedfrom the bore and the first closure member engages the seal, thepressure and fluid downstream of the stem causes the second closuremember to be moved to inhibit flow of fluid through the stem, therebyinhibiting the stem from spitting fluid during disconnection.

According to another preferred embodiment, a flow control device of thepresent invention comprises a valve body having opposite end portionsand a bore extending between the end portions, a closure member,including a rotatable ball member in the bore and having a passagewaytherethrough, for selectively opening and closing the bore to permit andprevent flow through the bore, and seal means, operating to encapsulatethe ball member, for sealing the bore to prevent unwanted fluid leakage.The seal operates to eliminate voids in which paint could collect andbreak free to contaminate the paint system during rotation of the ball.

Further, certain of the connection elements provided in the flexiblerecirculating conduit are comprised of a suitably configured polymericmaterial which combines strength and functional relationships anddecreases weight, the material preferably being of a glass-filled nylonwith a ceramic. Importantly, the fluid connection elements connectingthe supply to the inlet end of the conduit are comprised of stainlesssteel.

Still further, the improved spray gun of the present invention is alsocomprised of a suitably configured polymeric material, such asglass-filled nylon with a ceramic. This material reduces the overallweight of the spray gun while at the same time increasing the overallstrength and durability of the spray gun. Moreover, the improved spraygun further includes enlarged air passages which allows a greater volumeof air to pass through the spray gun to achieve better atomization atany pressure. Such an improved spray gun, decreases operator fatigue,increases durability, and further increases overall surface quality ofthe paint finish because of the reduced fatigue and the betteratomization.

The present invention overcomes many of the problems and disadvantagesassociated with prior art constructions, providing simple, economicalyet durable devices which can be directly connected to the fluid inletof a conventional spray gun or the improved spray gun and is easilymanipulable by an operator. Significantly, flakes and other particleswhich could interfere with the quality of the painted surface areinhibited and possibly eliminated.

Additional benefits and advantages of the present invention will becomeapparent upon a reading of the description of the preferred embodimentstaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a multiple spray station arrangement of arecirculating liquid paint coating composition supply system embodyingthe invention.

FIG. 2 is a view taken along line 2—2 of FIG. 1 illustrating a fluidconnector assembly connecting a paint supply line to a pair of paintstations according to the invention.

FIG. 3 is a section view of a ball valve fluid connector including aseal arrangement according to this invention.

FIG. 4 is an exploded view, in section, of the seal arrangement shown inFIG. 3.

FIG. 5 is a perspective view of an individual spray station andincorporating a coaxial recirculating conduit for supplying andreturning excess liquid paint coating composition to the supply systemembodying the invention.

FIG. 6 is an exploded view of an H-shaped fluid connector assembly forselectively connecting or disconnecting the supply system to therecirculating conduit according to this invention.

FIG. 7 is a partly exploded schematic view of the recirculating conduitshown in FIG. 3 and the fluid connectors therefor.

FIG. 8 is an exploded assembly view, in section, of a quick disconnectfluid connector assembly according to this invention.

FIGS. 9(A), 9(B) and 9(C) are side views in section showing the quickdisconnect fluid connector assembly of FIG. 8 being connected.

FIG. 10 is a section view of a swivel fluid connector.

FIG. 11 is a section view of a filter fluid connector assembly.

FIG. 12 is a section view of a restrictor fluid connector.

FIG. 13 shows the discharge end portion of the recirculating conduit.

FIG. 14 is a partially exploded section view of the discharge endportion shown in FIG. 13 and illustrates a fluid connector that isterminated to the conduit and a spring guard that is secured to thefluid connector for supporting the conduit and the termination thereforaccording to this invention.

FIG. 15 is a section view of a Y-shaped fluid coupler for mixing twocoating compositions according to this invention.

FIG. 16 illustrates another preferred embodiment of a recirculatingpaint supply conduit according to this invention, the conduit beingparticularly useful for mixing two paint coating compositions.

FIG. 17 illustrates another preferred embodiment of a recirculatingpaint supply system according to this invention, the conduit beingparticularly useful for mixing two paint coating compositions.

FIGS. 18-23 are views of a fluid flow regulator adapted to be connectedto a recirculating paint system according to this invention.

FIGS. 24-26 are views of a push to connect fluid coupling including acompression seal for a recirculating paint system according to thisinvention.

FIGS. 27(A) and (B) are sectional views of another preferred embodimentof a quick disconnect fluid connector assembly according to thisinvention.

FIGS. 28(A) and (B) are views of another preferred embodiment of theH-shaped fluid connector assembly according to this invention.

FIGS. 29(A)-(C) are views of yet another preferred embodiment of theH-shaped fluid connector assembly according to this invention.

FIG. 30 is a perspective view of the improved spray gun according tothis invention.

FIG. 31 is a cross-sectional view of the body of the improved spray gunaccording to this invention.

FIG. 32 is a front end view of the head portion of the improved spraygun according to this invention.

FIG. 33 is a top view of the head portion of the improved spray gunaccording to this invention.

FIG. 34 is a front view of a Y-shaped fluid fitting assembly accordingthis invention.

FIG. 35 is a exploded view of yet another preferred embodiment of theH-shaped fluid connector assembly according to this invention.

FIG. 36 is a cross-sectional view of a flare fitting utilized in theH-shaped fluid connector assembly of FIG. 35.

FIG. 37 is a cross-sectional view of another preferred embodiment of arestrictor fluid connector according to this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, and as may best be seen in FIG. 1, amultiple station recirculating liquid paint coating composition supplysystem 10 is illustrated. The supply system illustrated in FIG. 1illustrates a paint system for recirculating a single paint of aspecific color to each of the three spray stations identified at Numbers1, 2 and 3. In the embodiment shown, each station is in communicationwith a pressurized liquid coating or paint supply header 12 and a lowpressure paint return header 14. It will be appreciated that the spraystations illustrated in FIG. 1 can form a row of separate spray boothsto provide for a plurality of different coating compositions and/ordifferent colors. By way of example, each spray station may includetwelve different systems to supply twelve different colors of thedesired coating composition.

The paint supply system typically includes a supply tank and a supplypump for supplying the liquid coating paint composition under pressureto the supply header. The quantity of paint composition that is suppliedbut which is in excess of that required at the multiple stations isreturned to the supply via the return header. A supply branch line 16 ateach spray station is connected to the supply header 12 and in turn isconnected to a shut off valve at the entry to the spray booth whereby tosupply paint composition to a desired spray station. A return branchline 18 at each spray station is connected to the paint return header 14and to a shut off valve at the exit from the spray station whereby toreturn paint composition via the return header to the supply tank.

According to an important feature of the foregoing arrangement, thespray stations can be connected in series and in parallel. That is, eachof the plurality of branches permit selective branch lines to service aline of spray stations at different locations and each station to beprovided with a plurality of outlets. Additionally, two branch lines canbe used to service opposite sides of a common spray station.

As shown in FIG. 2, according to an important aspect of this invention,a specially configured fluid connector assembly 20 is provided to eithersupply or return the coating composition to each of two spray stations,such as to stations No. 2 and No. 3. As illustrated, a supply fluidconnector assembly 20 comprises a Y-shaped fluid fitting 22 including aninlet port 24 and two outlet ports 26, a generally straight tubularfluid conduit 28 for connecting the inlet port 24 to the supply branchline 16, a pair of angled tubular conduits 30 each having an inlet endconnected to one of the outlet ports 26 and an outlet end, and a pair ofball valves 32. The ball valve 32 has an inlet end 34 connected to theoutlet end 42 of one of the angled tubular conduits, and an outlet end36 connected to supply paint composition into the spray station. Eachball valve 32 can be closed to prevent fluid from passing into the spraystation, at that location, or opened to permit fluid to pass into thestation. When the fluid connector assembly 20 is used to return a paintcomposition, the outlet ports 26 would communicate the composition fromthe stations to the fluid fitting 22 and via the fluid conduit 28 intothe paint return header 14.

Preferably, the angled tubular conduits 30 have first and secondportions 40 and 42 with the first portions 40 extending along a firstaxis that is generally at an obtuse angle to the fluid conduit 28 andthe second portions 42 extending along a second axis that is generallyorthogonal (i.e., perpendicular to) to the fluid conduit 28. Generally,the first and second portions are joined by a curved portion 44 and aredisposed at an angle of about 130°-140°, and preferably at about 135° toone another. When connected to the fluid fitting, the fluid conduits 28and 30 form a generally Y-shaped configuration. While a T-section isknown for the purposes of dividing and/or directing a fluid to and alonga path that is generally orthogonal to the supply, it is believed thatthe 90° change in direction is too abrupt in a paint system and can leadto problems. The Y-shaped configuration of FIG. 2 is believed to enhanceconstancy of volume flow without paint coagulation and obviate anypossible adverse effects that may otherwise interfere with theuniformity of paint flow. While not shown, the Y-shaped fluid connectorassembly 20 could be used to return the low pressure paint compositionto the return header.

Referring to FIG. 34, another embodiment of a Y-shaped fluid fitting 400is shown. The Y-shaped fluid fitting 400 is similar to the Y-shapedfluid fitting 22 and is used for dividing and/or directing a fluid toand along a path that is generally orthogonal to the supply the way aconventional T-section is employed. The Y-shaped fluid fitting 400includes a body 402, preferably comprised of stainless steel having aninlet tubular conduit 404 and two outlet tubular conduits 406 and 408,respectively. The body 402 may either be configured to receive variouslength tubular conduits 404, 406 and 408 having appropriate angledportions, to be discussed shortly, and configured to be permanentlyaffixed to the tubular conduits 404, 406 and 408, such as by brazing. Ifpermanently affixed, the ends 410 of each tubular conduits 404, 406 and408 will contain various conventional coupling devices (not shown) toconnect the Y-shaped fluid fitting 400 into the supply system 10.

Preferably, as with the Y-shaped fluid fitting 20, the inlet tubularconduit 404 is generally a straight tube while each outlet tubularconduit 406 and 408 includes a first portion 412 extending along a firstaxis that is generally at an obtuse angle (i.e. about 120°) to the inlettubular conduit 404 and a second portion 414 extending along a secondaxis that is generally orthogonal (i.e., perpendicular) to the inputtubular conduit 404. The first and second portions 412 and 414 arejoined by a curved portion 416 and are displaced at an angle of about170°-150°, and preferably at about 160° to one another. By providing abody 402 which receives tubular conduits 404, 406 and 408, or byproviding permanently affixed tubular conduits 404, 406, 408, theY-shaped fluid fitting 400 may be coupled and conveniently usedthroughout the supply system 10 wherever the flow of fluid needs to bedirected orthogonal or perpendicular from a supply. By using gradualangled portions 44 and 416 having large obtuse angles (i.e. 130°-170°),the consistency of volume flow is enhanced and any possible adverseeffects that may otherwise interfere with the uniformity of paint flowis eliminated such as that associated with T-shaped fittings.

As shown in FIGS. 3 and 4, the ball valve 32 includes a valve body 46having opposite axial end faces 48 and 50, and a selectively threadedbore 52 extending between its end faces. The following elements arearranged in the bore in the following sequence: a first end fitting 54adjacent to the end face 48, a Teflon spacer 56, a stainless steelretainer member 58, the spacer and the retainer being threadablyconnected to the bore, the fluid sealed flow regulator member 38, and asecond end fitting 60 adjacent to the end face 50. The first end fitting54 includes a first portion that is threadably engaged with the bore anda second portion extending outwardly of the bore, the second end portionincluding a coupling nut 62 for connecting the ball valve 32 tostainless steel tubing. The second end fitting 60 includes a firstportion threadably engaged with the bore and an externally threadedsecond portion extending from the bore.

The fluid sealed flow regulator member 38 includes a spherical ball 64rotatably positioned in the bore of the valve body and having a passage66 extending therethrough, an operating rod 68 extending from the balland through the valve body, and a handle 70 connected to the operatingstem for rotating the ball in the bore whereby to position the passage66 relative to the bore. An O-ring 72 is provided to seal around the rod68 where it passes through the valve body.

According to this invention, the valve body 46 is comprised of apolymeric material, such as glass filled nylon with a ceramic orstainless steel. Preferably, the externally threaded first portions ofthe end fittings are embedded in the polymeric material or formed intothe stainless steel. Further, except for the elements that must beresilient to complete a seal, it is contemplated that the end fittings,the retainer member and the ball that makes contact with the paintcomposition be comprised of stainless steel, or other suitable materialhaving a resistance to attack by the paint. It is believed that when thepaint is subject to metal contact, paint flakes/particles are inhibitedin the paint system downstream of the supply and return.

Importantly, a combination bearing and seal arrangement is providedwhereby to seal the ball 64 relative to the bore. Although the use ofseals which engage the ball element are known, leakage and paint flakeshas oftentimes been a problem.

According to this invention, a pair of cylindrical cup-shaped valveseats 74 are adapted to be brought into abutting relation with oneanother and encapsulate the rotatable spherical ball 64 therebetween.Each valve seat 74 has a flat endwall 76 to sealingly abut the retainermember 58 or the second end fitting 60, depending on whether the valveseat is upstream or downstream of the ball, and a generally cylindricalwall 78 having an axial mating face 80 and forming a semisphericalcavity. The mating faces are axially abutted to form an axial sealwithout introducing any voids. The outer periphery of the cylindricalwall 78 is adapted to engage the bore to form a seal therewith. Theendwall 76 has an opening 82 to pass fluid between the valve seats whenball is positioned so that fluid will pass through its passage 66.

In operation, the valve seats 74 are placed on opposite sides of theball 64 and axially pressed together, whereby the mating faces 80 areabutted to form a substantially void free axial seal, and thecylindrical walls 78 form a cavity to totally encapsulate the ball 64.This bearing cavity completely encapsulates the ball so that no paintcan accumulate in the interface between the ball and the stainless steelor polymeric body of the valve, which material would, when dried, leadto the possibility of paint flakes/particles breaking free duringrotation of the ball 64. There are no crevices or threads to collectpaint or dirt where it can harden and contaminate later paint jobs.

FIG. 5 is a perspective view, embodying the invention, of an individualspray booth 84 in one of the paint stations and a recirculating conduit86 used by an operator to direct the liquid paint coating compositionfrom the supply system to a spray gun 88. It is to be understood thatthe spray booth is not exclusively limited to the supply system andpaint station arrangement disclosed.

As shown, a product to be painted such as an automotive vehicle 90, ismoved through the spray booth by a conveyor system 92. The walls of thespray booth are formed from rectangularly shaped pads of removableplastic film so that walls may be cleaned by simply removing the layersof film.

In the embodiment shown, the supply and return lines from the Y-shapedfluid connector assembly 20 enter the spray booth through the ceiling 94and into an H-shaped connector assembly 96. Of course, the supply andreturn could enter in a manner other than that shown (e.g., the linescould enter through a wall of the station). The recirculating conduithas one end thereof connected to the supply and return lines of thepaint system via the H-shaped connector 96 and its other end connectedto the spray gun 88.

According to an important feature of this invention, the components ofthe spray gun 88 are preferably comprised of a polymeric materialwhereby to contribute to an overall decrease in the weight of theconduit handled by the operator. Preferably, the polymeric materialwould be glass filled nylon with a ceramic. However, the spray gun couldalso be comprised of metal.

According to this invention, as shown in FIG. 6, the H-shaped fluidconnector assembly 96 is provided for selectively connecting the supplyand return branch lines 16 and 18 of the paint supply to the inlet andreturn ends of the recirculating conduit 86 or interrupting the supplyof paint to the recirculating conduit 86 whereby the recirculatingconduit 86 may be disconnected for service, cleaning or the like. TheH-shaped fluid connector assembly 96 is formed by valves 96 b and 96 ceach having an internal construction as described above for the ballvalve 32. Valves 96 a are of the bulkhead type and each has anexternally threaded sleeve portion 96 e at one of its ends forcompleting a fluid connection, respectively, to the supply and returnheaders 12 and 14 of the paint system, an internally threaded bore atthe other of its ends to threadably receive the threaded end portion ofa fluid coupler 96 d, and a side branch 96 f fitted with a rotatablefluid coupler 96 d. The valves 96 b and 96 c are the same and each hasan externally threaded sleeve portion 96 g and 96 h at its oppositeends. The bypass valve 96 b has its opposite sleeve portions 96 g and 96h threadably engaged, respectively, with the respective fluid couplers96 d in the side branches of the valves 96 a. Each valve 96 c has one ofits sleeve portions 96 g threadably connected with a fluid coupler 96 dof a respective valve 96 a and the other of its sleeve portions 96 hthreadably connected to the respective supply and return lines of therecirculating conduit 86, in a manner to be described.

In operation, when the valves 96 c are open and the bypass valve 96 b isclosed, fluid may flow to and from the paint supply and into therecirculating conduit 86 whereby to communicate to the spray gun 88. Ifhowever the valves 96 c are closed and the 96 b is open, fluid cannotpass into the recirculating conduit 86 whereby the recirculating conduit86 may be replaced, or removed, if desired.

Referring to FIGS. 28(A) and 28(B), the H-shaped fluid connectorassembly 96 is shown with a connecting mechanism 97. The connectingmechanism 97 includes a partial annular connecting member 99 constructedof a polymeric material or other suitable material and a handle 101rotatably mounted to the annular member 99. The annular member 99 ispivotably mounted to each handle 70 of the ball valves 32 comprising thevalves 96 b and 96 c.

Referring specifically to FIG. 28(A), the supply and return valves 96 care open and the bypass valve 96 b is closed whereby fluid may flow toand from the paint supply from the supply and return branch lines 16 and18 to the inlet and return ends of the recirculating conduit 86. Uponpivotably rotating the annular member 99 clockwise using the handle 101,each handle 70 of the ball valves 32 are simultaneously rotated tosimultaneously close both valves 96 c and open bypass valve 96 b, asshown in FIG. 28(B). The handles 70 are simultaneously moved by a usermerely grasping the rotatable handle 101 and applying a clockwise force.Upon closing both valves 96 c and opening bypass valve 96 d, fluid isinhibited from passing into the recirculating conduit 86 whereby therecirculating conduit 86 may be quickly replaced or removed, or checkedfor pressure differential or loss, if desired.

The connecting mechanism 97 easily and efficiently allows individualspray booths 84 or entire spray stations to be bypassed and removed fromthe supply system 10. For example, if there is a leak or pressure lossin the system 10, each spray booth 84 must be individually removed fromthe system 10 in order to determine if a loss of pressure is occurringin that particular spray booth 84. With approximately two to three spraystations, each having between 12 and 20 individual spray booths 84, theprocess of individually removing each spray booth 84 from the system 10can take many man hours if each ball valve 32 must be individuallyturned. In addition, by having each handle 70 pivotably connected to theannular member 99, this eliminates human error of turning the ballvalves 32 incorrectly or inadvertently not turning a ball valve 32.

Referring to FIGS. 29(A)-29(C), the H-shaped fluid connector assembly 96is shown with another embodiment of a connecting mechanism 103. Theconnecting mechanism 103 includes a partial annular connecting member105 constructed of a polymeric material or other suitable material suchas steel or aluminum. The annular member 105 is pivotably mounted toeach handle 70 of the ball valves 32 comprising the valves 96 b and 96c. The handle 70 a of the supply valve 96 c has an elongated portion 107which acts as a handle to move the connecting mechanism 103, which willbe discussed in detail shortly.

Referring specifically to FIG. 29(A), the supply and return valves 96 care open and the bypass valve 96 b is closed whereby fluid may flow toand from the paint supply from the supply and return branch lines 16 and18 to the inlet and return ends of the recirculating conduit 86. Uponpivotably rotating the annular member 103 clockwise using the elongatedportion 107 of handle 70 a, each handle 70 of the ball valves 32 aresimultaneously rotated to simultaneously close both valves 96 c and openbypass valve 96 b, as shown in FIG. 29(B). The handles 70 aresimultaneously moved by a user merely grasping the elongated portion 107and applying a clockwise force. Upon closing both valves 96 c andopening bypass valve 96 b, fluid is inhibited from passing into therecirculating conduit 86.

As shown in FIG. 29(B), there are two (2) H-shaped fluid connectorassemblies 96 and 96′ shown with one behind the next. The first assembly96 is shown with the valves 96 c closed and the bypass valve 96 b open.The second assembly 96′ is shown with the valves 96 c open and thebypass valve 96 b closed. By positioning the connector assemblies 96 and96′, as well as other connector assemblies 96 one behind the next, thisallows a user to merely look down the line of connector assemblies 96 todetermine which particular assemblies 96 have bypassed the recirculatingconduit 86. This also permits the assemblies 96 to be positioned inclose proximity behind one another because the elongated portion 107allows a user's hand to easily grasp the portion 107 in order to move itclockwise or counter clockwise.

Referring to FIG. 29(C), the handle 70 b of the return valve 96 c isshown taken along the line 29(C) of FIG. 29(B). The handle 70 b includesa tang 109 which acts as a stop mechanism to inhibit the handle 70 bfrom being turned clockwise more than about 90° relative to the valve 96c such that the handle 70 b is substantially perpendicular to the axialaxis of the valve 96 c, as shown in FIG. 29(B). The tang 109 alsoinhibits the handle 70 b from being turned counter clockwise more than90° such that the handle 70 b is substantially parallel along the axialaxis of the valve 96 c, as shown in FIG. 29(A). Because the handle 70 bis connected to the other handles 70 of the valves 96 b and 96 c, viathe connecting mechanism 103, the other handles 70 are also inhibited inmovement substantially the same as handle 70 b. This ultimately enablesa user to know when the ball valves 32 are fully opened or fully closed,as well as preventing damage to the ball valves 32 from excessiverotation of the handles 70.

According to this invention, a hollow funnel-shaped seal member 98 islocated between mating conical surfaces formed in the sleeve portion ofthe valves 96 a, 96 b or 96 c and in the fluid coupler 96 d and axiallycompressed into fluid sealed relation. Preferably, the seal member 98 iscomprised of Teflon and includes a cylindrical portion at one end and aconical portion at the other end. The sleeve portion includes aninwardly tapering conical wall and an interior cylindrical wall wherebyto form a recess sized to nestingly receive the seal member 98. Couplingrotation of the fluid coupler 96 d desirably results in a compressionfluid seal between the mating members.

Referring to FIGS. 35 and 36, another preferred embodiment of a H-shapedfluid connector assembly 420 is shown for selectively connecting thesupply and return branch lines 16 and 18 of the paint supply to theinlet and return ends of the recirculating conduit 86. The H-shapedfluid connector assembly 420 is formed by valves 96 b and 96 c eachhaving an internal construction as described above for the ball valve32. The previous T-shaped valves 96 a in the H-shaped fluid connectorassembly 96 are replaced with T-shaped fittings 422. The fittings 422each have an externally threaded sleeve portion 424 for completing afluid connection, respectively, to the supply and return branch lines 16and 18 of the paint system 10. At the end opposite the externallythreaded sleeve portion 424 and also perpendicular to the externallythreaded sleeve portion 424 are flare fittings 426.

The flare fittings 426 include a male conical surface 428 which engagesa female conical surface 430 of the valves 96 b and 96 c. Each flarefitting 426 engages the valves 96 b and 96 c, via a rotatable internallythreaded swivel nut 432, which threadably engages externally threadedsleeve portions 96 g and 96 h of the valves 96 b and 96 c (see FIG. 36).By utilizing the flare fitting 426 having the conical male surface 428which engages the female conical surface 430, this eliminates the needfor the connections to utilize pipe dope, as well as eliminates the needfor any type of internal threading within the T-shaped fitting 422 whichcould accumulate paint over time thereby causing flaking. Moreover, thesupply and return branch lines 16 and 18 also include flare fittings426, thereby eliminating the need for pipe dope when coupling theH-shaped fluid connector assembly 420 to the paint system 10. Thisenables the one piece H-shaped fluid connector assembly 420 to replace acollection of ball valves which are generally assembled manually andtherefor relatively time consuming to install.

Coupled to the handles 70, 70 a and 70 b is a solid annular connectingmember 434. The annular connecting member 434 is pivotably coupled toeach handle 70 of the ball valves 32 at pivot points 436 similar to thatshown in FIGS. 28A to 29B. Pivotably coupled to the annular connectingmember 434 is a handle member 438 which is ridgedly mounted axially tothe handle 70 a similar to the extension 107 shown in FIGS. 29A and 29B.The annular connecting member 434 is constructed of a suitable materialsuch as steel, aluminum or a polymeric material. Upon pivotably rotatingthe annular connecting member 434 clockwise using the handle 438, eachhandle 70 of the ball valves 32 are simultaneously rotated tosimultaneously close both valves 96 c and open bypass valve 96 b,similar to that shown in FIG. 29B. Upon pivotably rotating the annularconnecting member 434 counter-clockwise by use of the handle 438, eachhandle 70 of the ball valves 32 are simultaneously rotated tosimultaneously open both valves 96 c and close bypass valve 96 b, asshown similar to FIG. 29A.

FIG. 7 is a partly exploded schematic view of the recirculating conduit86 used in the paint supply system, including a pressurized paint supplyline for supplying paint to the nozzle of the spray gun 88 in a quantityin excess of that required and a return line for recirculating excesspaint from the spray gun. The recirculating conduit comprises a pair ofhoses 100 and 102 arranged coaxially and including an outer hose 100which forms a supply conduit, an inner hose 102 which forms a returnconduit, a Y-shaped coupling 104 attached to the hoses to direct fluidinto the passage formed between the hoses 100 and 102, and a fluidfitting 106 secured to the discharge end of the outer hose 100. Thecoupling 104 includes an inlet end 110 connected in fluid tight relationto the supply branch line 16 via the H-shaped connector assembly 96, areturn end 112 connected in fluid tight relation to the return branchline 18 via the H-shaped connector assembly, and an outlet end 114. Thefluid fitting 106 is adapted to connect the discharge end of therecirculating conduit 86 with a fluid fitting assembly 108 forconnection to the spray gun 88.

The recirculating conduit 86 and the Y-shaped coupling 104 are similarto those disclosed in U.S. Pat. No. 5,195,680. Generally, the outer hose100 is of a composite construction to include outer and inner layers,the outer layer being comprised of a material having high strength andflexibility. A suitably material is a mixture of nylon and polyurethaneplastics. The inner layer and the inner hose 102 are comprised of amaterial which is resistant to attack by the liquid coating compositionsin contact therewith, nylon being one suitable material.

The fluid fitting assembly 108 between the spray gun 88 and the fluidfitting 106 at the discharge end of the recirculating conduit comprises,in the following sequence, a quick disconnect fluid coupling assembly118 which is adapted to be attached to the spray gun, a swivel fluidconnector 120, a filter fluid connector 122, and a flow control orrestrictor fluid connector 124 which is adapted to be coupled to thefluid fitting 106. According to a particular feature of this invention,it is important that the fluid fittings withstand attack of the liquidcoatings in contact therewith yet be sufficiently light in weight suchthat total weight of the spray gun, fittings and hose which must be heldand maneuvered manually be held to a minimum. According to thisinvention, this objective is achieved by selective manufacture of thefitting elements of a polymeric material. As will be discussed furtherhereinbelow, the quick disconnect, the swivel, the filter, therestrictor, and the fluid discharge connector at the end of the hose areselectively comprised of a polymeric material such as glass filled nylonwith a ceramic.

As shown best in connection with FIG. 8 and in the coupling sequenceillustrated FIGS. 9(A) to 9(C), the quick disconnect fluid couplingassembly 118 includes a centrally bored quick disconnect stem 126 havinga pin 128 extending radially therefrom, and a centrally bored ball quickdisconnect connection 130 having a bayonet slot 132 at its forwardmating end to interengage with the radial pin to couple the twotogether. The quick disconnect stem 126 includes an elongatedcylindrical stem 134 having an internally threaded coupling nut 136rotatably mounted thereto for connection to a threaded end of the spraygun 88 and an axial forward end portion 137 adapted to be inserted intothe valve member. The stem 134 has an axial end face 138 which protrudesaxially forward of the stem body and a central bore 140 therethrough forpassing fluid. The end face 138 is slightly semispherical in shape andis provided with a central aperture 142 and one or more peripherallydisposed apertures 144, each aperture communicating with the centralbore 140.

The quick disconnect connection 130 includes forward and rearward shellportions 146 and 148 which are threadably engaged to form a valve body150 having a generally cylindrical stepped bore 152 extending centrallybetween the forward and rearward ends of the body, a pair of sealmembers 154 and 156 disposed in the bore to seal about the outerperiphery of the stem 134 and the bore 152 of the valve body 150, and aclosure member in the form of a spherical ball 158 normally biased by acoil spring 160 into engagement with the seal member 156 to preventfluid from passing through the bore. The forward end of the shellportion 146 forms a cylindrical socket to receive the stem 134 andincludes the bayonet slot 132 to engage with the pin 128 during axialinsertion of the stem into the valve body. The rearward end of the shellportion 148 includes a conical socket 162 for compression mating with acorresponding conical face on the swivel fluid connector 120.

Preferably, the shell portion 146 is comprised of a metal, such asstainless steel, whereby to endure the forces and wear occasioned duringconnection and disconnection to the stem 134. To reduce the weight ofthe conduit system, the shell portion 148 is formed of glass-fillednylon with a ceramic, or other suitable polymeric material not subjectto attack by the paint material.

The seal members 154 and 156 are generally planar, circular and have apair of flat faces, an outer circumference, and a central passage 164and 166 extending between its respective faces. The seal members 154 and156 are mounted in the bore 152 in sandwiched relation between theshoulders 168 and 170 formed on the shell portions 146 and 148. Theouter diameter of each seal member 154 and 156 is preferably slightlygreater than the inner diameter of the bore 152 whereby to provide aninterference fit therebetween. When the shell portions 146 and 148 arebrought together to assemble the valve body, the seal members 154 and156 are compressed together to form an axial seal therebetween and aradial seal with the bore 152 of the valve body 150.

Preferably, the confronting faces of the seal members 154 and 156 areformed to include a conical skirt. As shown, the seal member 154includes a conical skirt 172 which tapers inwardly and into encirclingengagement about the entrance to the central passage 166 through theseal member 156. The seal member 156 includes a conical skirt 174 whichexpands outwardly and into sealing engagement with the inner wall of thebore 152 to complete a 360° sealing engagement therewith. The forwardend 176 of the skirt 172 defines a restricted opening of the sealpassage that is dimensioned to engage the outer periphery of the stem134 prior to insertion of the stem into the passage 166 of the sealmember 156. During insertion, the forward end 176 centers the stem 134relative to the passage 166 and is forced against the seal member 156,thus to inhibit any flashback of the high pressure paint.

The closure member 158 is a spherical ball which seats, in part, in theentry to the central passage 166 and against the end face of the sealmember 156. The coil spring 160 has its opposite ends disposed against ashoulder 178 of the valve bore and the closure ball 158 whereby tonormally axially force the ball into the central passage, therebycompressing the seal material around the passage and forming a fluidseal thereabout.

The central passages 164 and 166 formed by the conical skirt 172 of theseal member 154 or by the wall of the passage through the seal member156 has a diameter that is slightly less than the outer cross-sectionaldiameter of the stem 134 whereby to provide a sealed interference fittherebetween upon coupling engagement. Importantly, the stem will engageand seal with the central passages 164 and 166 prior to engaging theclosure member.

During coupling, the stem 134 is axially inserted into the front matingend of the valve body 150 and the pin 128 engaged with the slot 132 inthe socket thereof, twisted, and progressively inserted. The forward endportion 137 of the stem 134, when inserted, will be successively engagedwith the seal members 154 and 156 to seal against leakage, during whichtime the closure ball 158 is forced against the seal member 156 toprevent fluid passage. Ultimately, upon complete interengagement betweenthe pin 128 and the slot 132, the end face 138 of the stem 134 willengage and axially force the closure ball 158 away from fluid preventingclosing relation with the seal member 156.

In FIG. 9(A), the forward end portion 137 of the stem 134 has beenaxially inserted into the bore 152 by an amount sufficient to engage theconical skirt 172 of the seal member 154, whereby to be in sealingengagement therewith, and to force the forward end 176 of the skirtagainst the seal member 156. The penetration of the stem 134 is suchthat a fluid seal is formed therebetween but the stem does not engagewith the closure ball 158, which remains biased against and in sealingrelation against the rearward end face of the seal member 156.

In FIG. 9(B), the forward end portion of the stem 134 has been insertedinto the bore 152 by an amount sufficient to penetrate into the centralpassage 166 of the seal member 156. The outer periphery of the stemestablishes sealing engagement with the seal member 156, withoutdisturbing the sealing engagement between the closure ball 158 and endface of the seal member 156. The stem is also in sealed engagement withthe conical skirt 172.

In FIG. 9(C), the axial end face 138 of the stem 134 has reached anddriven the closure ball 158 axially rearward from its engagement withthe end face of the seal member 156 whereby fluid is permitted to passthrough the valve body 150, through the apertures 144 in the end face138, and through the central bore 140 of the stem 134. The closure ball158 would then be seated in the central aperture 142 formed in the axialend face 138. Importantly, during withdrawal, the controlled sealingengagement between the stem 134 and the seal members 154 and 156 allowsgradual reseating of the closure ball 158 against the end face of theseal member 156 and into the central passage 166 whereby to inhibitpaint from splashing outwardly.

Referring to FIGS. 27(A) and 27(B), another preferred embodiment of thecentrally bored quick disconnect stem 126 is shown connected anddisconnected from the centrally bored quick disconnect connection 130.The centrally bored quick disconnect stem 126 in FIGS. 27(A) and 27(B)includes a closure member formed from a spherical ball 127 which freelymoves between the pin 128 and a spherical rim or ledge 129 formed in thecentral bore 140 of the stem 134. Upon coupling the quick disconnectstem 126 to the quick disconnect connection 130, similarly to that shownin FIGS. 9(A)-9(C), pressure and fluid in the conduit upstream from theclosure member 158 causes the spherical ball 127 to be displacedadjacent to the pin 128. Fluid then flows through the apertures 144 andinto the central bore 140 of the elongated cylindrical stem 134 andpasses between the spherical ball 127 and the spherical ledge 129, asshown in FIG. 27(A). The pressure downstream of the spherical ball 127is thus substantially the same as the pressure upstream of the closuremember 158 when the quick disconnect stem 126 is connected to the quickdisconnect connection 130.

Referring to FIG. 27(B), upon disconnection of the quick disconnect stem126 from the quick disconnect connection 130, the closure member 158seals against the seal member 156 as previously discussed to inhibitflashback of fluid from the recirculating conduit. In addition, thepressure downstream from the spherical ball 127 and the quick disconnectstem 126 causes the spherical ball 127 to be moved into engagement withthe spherical ledge 129 formed within the central bore 140 of the stem134. Movement of the spherical ball 127 against the spherical ledge 129seals the central bore 140 to inhibit any flashback of fluid from thequick disconnect stem 126 upon disconnection from the quick disconnectconnection 130. Moreover, this also allows the spray gun 88 to be movedand stored without fluid leaking from the central bore 140 as long as apressure is maintained upstream of the spherical ball 127. Uponconnection of the quick disconnect stem 126 with the quick disconnectconnection 130, the spherical ball 127 is moved away from the sphericalledge 129 since the pressure downstream of the spherical ball 127 isgenerally slightly less than upstream upon initial connection of thevalve member 126 to the quick disconnect connection 130.

FIGS. 10, 11 and 12 disclose, respectively, details of the swivel fluidconnector, the filter fluid connector and the restrictor valve. Theswivel fluid connector 120 includes a body 180 having a bore extendingbetween forward and rearward portions thereof, and a rotatable couplingnut 182 on the forward portion to couple to the quick disconnect fluidcoupling assembly 118. The rearward portion is externally threaded andhas an internal conical wall 184 to form a portion of a compressionconnection when connected to the filter fluid connector 122. Preferably,the body 180 is comprised of a suitable polymeric material, such asglass filled nylon with a ceramic. Desirably, the swivel fluid connector120 allows the recirculating conduit 86 to rotate relative to the spraygun 88 and prevent forces from distorting the integrity of therecirculating conduit. Depending on the application, the coupling nut182 may either be of a polymeric material, or metal, such as stainlesssteel.

The filter fluid connector 122 is similar to that disclosed in U.S. Pat.No. 4,442,003, the teachings of which are incorporated herein byreference. Generally, the filter fluid connector 122 includes athimble-shaped filter element 186 which is captivated between first andsecond ferrules 188 and 190, the first ferrule 188 being externallythreaded for attachment to the restrictor fluid connector 124 and thefilter element being affixed to the second ferrule 190. Importantly,however, the ferrule 188 is comprised of glass filled nylon with aceramic and the ferrule 190 is comprised of stainless steel.

The restrictor fluid connector 124 is similar to that disclosed in U.S.Pat. No. 4,106,699, the teachings of which are incorporated herein byreference, and also in the aforementioned U.S. Pat. No. 5,060,861. Therestrictor fluid connector 124 includes a centrally bored fluid housing192, a coupling nut 194 mounted to the forward end portion of thehousing for attachment to the ferrule 190 of the filter fluid connector122, and a flow plate 196 and adjustable flow restrictor 198 secured inthe bore of the fluid housing 192. Importantly, however, the fluidhousing 192 is comprised of glass filled nylon with a ceramic.

Referring to FIG. 37, another embodiment of a restrictor fluid connector440 is shown. The restrictor fluid connector 440 includes a moldedone-piece body 442 having an externally threaded input port 446 and anexternally threaded return port 444. The restrictor fluid connector 440is used in place of the restrictor fluid connector 124 when anon-coaxial recirculating conduit 86 is used. In other words, a supplyhose similar to hose 100 is coupled to the externally threaded inputport 446 while a return hose similar to hose 102 is coupled to theexternally threaded return port 444. The body 442 of the restrictorfluid connector 440 is a one-piece restrictor formed from a polymericmaterial such as glass filled nylon with a ceramic. The input port 446connects to an input fluid passage 452 which flows into a central fluidpassage 450 and the return port 444 includes a return fluid passage 448which also flows from the central fluid passage 450. The central fluidpassage 450 includes an internally threaded end portion 454 whichreceives a plug 456 after the fluid passage 450 is formed into the body442. The restrictor fluid connector 442 is coupled to the ferrule 188 ofthe filter fluid connector 122, with a coupling nut 458 similar to therestrictor fluid connector 124.

The restrictor fluid connector 440 further includes a flow plate 460 andan adjustable flow restrictor 462 secured within a bore 464 of the body442, similar to the restrictor fluid connector 124. By constructing therestrictor fluid connector 440 with a single body 442 comprised of apolymeric material, this eliminates the need to provide a restrictorfluid connector body formed from multiple parts which are weldedtogether, such as when the restrictor fluid connector is comprised ofstainless steel. This use of welded together multiple parts increasesthe overall production cost for such a restrictor, as well aspotentially creates voids or crevices where the multiple parts are matedtogether which may accumulate paint over time and thereby flakes andparticles get on the painted surface. Accordingly, the restrictor fluidconnector 440 is therefor lower in cost to produce, lighter thanconventional stainless steel restrictors and eliminates potential voidswhich can accumulate paint and dirt.

Turning to FIGS. 13 and 14, according to an important feature of thisinvention, the discharge end of the recirculating conduit 86 includes aflexible strain relieved termination, including the fluid fitting 106that is terminated to the outer hose 100 of the recirculating conduit,and a helical coil sheath 200 to engage the fluid fitting andsupportingly encircle the outer periphery of the recirculating conduit.Preferably, the fluid fitting 106 comprises a pair of fluid housings 202and 204 which are threadably engaged to form the fitting. The fluidhousing 202 includes a forward end portion onto which is mounted aninternally threaded coupling nut 206 to connect to the restrictor fluidconnector 124 and an externally threaded rearward end portion tothreadably connect to the fluid housing 204. The fluid housing 204includes a rearward end portion 208 to which the outer and inner supplyand return hoses 100 and 102 of the recirculating conduit 86 aresecured. Preferably the fluid housings 202 and 204 are comprised ofglass filled nylon with a ceramic.

According to this invention, the rearward end portion 208 of the fluidhousing 204 is externally threaded or formed to include helicalconvolutions 210 that extend radially outward therefrom with the senseof the convolutions (or thread) being opposite to the helical sense ofthe internal thread formed in the coupling nut 206. Further, accordingto this invention, the coil sheath 200 is formed by a wire that ishelically coiled into an axially elongated cylinder and the helicallycoiled wire is threadably engaged within the grooves of the convolutions210 formed on the fluid housing. As configured, coupling rotation of thecoupling nut 206 on the fluid fitting 106 tends to tighten the threadedconnection between the coils of the sheath and the helical groovesformed by the external thread.

Further, according to this invention, the forward end of the fluidfitting 106, enclosed by the coupling nut 206, is generally conicallyshaped. As such, the mated relation results in a compression fit.

FIGS. 15-17 illustrate preferred embodiments of a paint system accordingto this invention in which two paint coatings are applied at the sametime. According to these embodiments a pair of respective coaxialrecirculating conduits 86 a and 86 b are connected, respectively, attheir supply end to a paint coating source to supply same under pressureto the discharge end of the conduit. For example, the firstrecirculating conduit 86 a could recirculate a clear coat paint and thesecond recirculating conduit 86 b could recirculate a base paint. Aunique Y-shaped fluid connector 212 operates to receive the flow ofpaint composition from each of the two recirculating conduits, mix theflows into one, and supply this mixed flow to the spray gun 88.

Referring to FIG. 15, the Y-shaped fluid connector 212 includes twoinlets 214, an outlet 216, a central chamber 218 for receiving the twocoatings from the inlets 214, and a nylon mixing element 220 in thechamber for mixing the two coatings. A check valve 222 is positioned ateach inlet to allow the base coat or clear coat to flow from the inletto the outlet but not to flow into to other inlet. A slot 224 in thecheck valve 222 permits fluid to flow through the check valve when thefluid is being discharged from the recirculating conduit. The nylonmixing element 220 comprises a generally axial fin formed (i.e.,twisted) helically about its axis. The fin rotates about its axis to mixthe paints together as the clear coat and base coat are received in thechamber.

The recirculating conduits 86 a and 86 b preferably include a restrictorfluid connector 124, as described above. As shown in the paint system ofFIG. 16, a single restrictor connector 124 is positioned at the outlet(i.e. discharge) end of the Y-shaped connector 212 whereby to restrictthe flow of paint to the spray gun. Alternatively, as shown in the paintsystem of FIG. 17, two restrictor connectors 124 are provided, one foreach inlet to the Y-shaped connector 212. The restrictor fluid connector124 would advantageously permit the user to vary the amount of eitherpaint composition being supplied to the mixer.

It is believed that the fluid connectors, which connect the paint supplyto the conduits, need to have their inner components of stainless steel,although the outer shell still may be made of glass-filled nylon with aceramic or metal. It is believed that making the components fromstainless steel results in less degradation of the paint of thosesurfaces that contact the paint. Although not shown, it is to beunderstood that in certain applications the coaxial recirculating (i.e.,the hose within a hose) conduit described above could be replaced withfour separate conduits.

Referring now to FIGS. 18-23, according to another important feature ofthis invention, a paint flow regulator 226 for use in recirculatingliquid coating composition systems is adapted to provide a specific flowof a single coating material to the spray gun 88. The flow regulator 226assures a continuous supply of a uniform liquid coating to the nozzle ofthe spray gun 88 at an adjustable desired pressure.

The flow regulator 226 includes a first and second housing 228 and 230having respective mating faces 232 and 234 and forming respectivechambers 236 and 238, inlet and return lines 240 and 242 communicatingwith the chamber 236 formed in the housing 228, an outlet line 244communicating with the mating face 232, a fluid passage 246 extendingbetween the flow chamber 236 and the mating face 232, and a diaphragm248 and a gasket 250, the housings being combinable whereby the outerperiphery of the diaphragm 248 and the gasket 250 are compressed betweenthe mating faces 232 and 234 and the diaphragm isolates the chambers 236and 238 from one another. A series of fluid recesses 252 arranged intothe shape of a crucifix are formed in the front mating face 232 with onefluid recess 252 thereof being in direct fluid communication with theoutlet line 244. The crucifix has its center located on the passage 246and the respective recesses extend radially outwardly from the axis ofthe passage. The inlet and return lines 240 and 242 terminate in aconventional fluid connector and the outlet line 244 terminates in aconventional quick connect fluid connector.

Flow is regulated, in part, by an elastomeric seal 254 having a throughbore 256 and mounted in the flow chamber 236 for sealing the entrance tothe passage 246 and an axial push rod 258 mounted for axial movement inthe bore 256 and in the passage 246. The push rod 258 has a shaped head260 disposed in the flow chamber 236 and movable into sealing engagementwith the wall of the through bore 256, a drive shoulder 262 positionablein the passage adjacent to the mating face 232, and a threaded forwardend 264 extending through the diaphragm 248 and into the chamber 238.The cross-section of the drive shoulder 262 and the passage 246 adjacentthe front mating face 232 are substantially the same whereby the driveshoulder 262 will inhibit flow from the flow chamber 236. Access to theflow chamber 236 is afforded by a plug 266 threadably secured in a boreformed in the housing 228.

Preferably the housings 228 and 230 and the plug 266 are comprised of apolymeric material, such as glass filled nylon with a ceramic. To form acomplementary transition between the polymeric material of the housing228 and to transmit force, flat annular washers 268 and 270 are locatedbetween the mating face 232 and the diaphragm 248, the washer 268 beingof polymeric material and abutted against the mating face 232 and thewasher 270 being of a suitable metal and abutted against the diaphragm.

Movement of the push rod 258 is controlled, in part, by a flat circularforce plate 272 disposed in the chamber 238, an axial flow controlplunger 274 extending through a wall of the housing 230 into the chamber238 to engage the force plate 272, a flat polymeric annular washer 276in the chamber 238 and abutted against the diaphragm 248, and acylindrical coil spring 278. The coil spring 278 is comprised of flatcoils and has its opposite axial ends abutted, respectively, against theannular washer 276 and the force plate 272. The forward end 264 of thepush rod 258 is provided with a cap 280 which engages the washer 276,the cap 280 and the drive shoulder 262 operating to clamp the washers268, 270 and 276 and the diaphragm 248 together. The flow controlplunger 274 is threadably engaged with the housing 230 and adapted to beincrementally advanced into and outward of the chamber 238, the inwardadvance of the flow control plunger 274 increasing the spring forceacting on the washer 276 (and thus the fluid pressure needed to overcomethe spring load).

The operation of the flow regulator 226 is shown in sequence in FIGS.20-22. Fluid flow is regulated through the flow regulator 226 by theaxial reciprocation of the push rod 258 within the passage 246. Duringoperation, the flow chamber 236 continuously receives and recirculates ahigh volume of liquid paint whereby to maintain the liquid constituentstherein in the form of a substantially uniform dispersion. The paint isintroduced into the flow chamber 236 through one sidewall of the flowchamber such that the paint will impinge on an apertured turbulizersleeve 267 extending from the plug 266 and against an opposite sidewallto develop a swirling action to maintain the paint constituentsuniformly dispersed.

Initially, as shown in FIG. 20, the coil spring 278 normally biases thepolymeric washer 268 against the mating face 232, thereby resulting inthe washer 268 forcing the drive shoulder 262 of the push rod 258 intoposition in closing relation with the outlet of the passage 246.Pressurized liquid is then introduced into the flow chamber 236 via theinlet line 240. If the fluid pressure is lower than the spring force,the driver shoulder 262 will not move but will act to prevent fluid fromflowing through the passage 246. The fluid will return to the supply viathe return line 242.

As shown in FIG. 21, as the fluid pressure increases, the force actingon the head 260 of the push rod 258 will exceed the spring force,thereby driving the drive shoulder 262 of the push rod towards thesecond housing 230 and the washer 268 from covering relation against themating face 232 and with the recesses 252. Fluid is allowed tocommunicate via the recess 252 a and to the outlet line 244. Excessfluid will return to the supply via the return line 242.

Finally, as shown in FIG. 22 should the pressure increase to a levelthat the fluid force acting on the head 260 is greater than the springforce, the head 260 will move into seated relation with the wall of thethrough bore 256 of the seal 254 mounted in the fluid chamber 236. Inthis condition, the push rod 258 will prevent fluid from passing throughthe passage 246 and the fluid will return to the supply via the returnline 242.

According to another feature of this invention, a push to connect fluidcoupling 282 is shown in FIGS. 24-25. In this fluid coupling, acylindrical fluid conduit 284 has an end portion 286 adapted to beinserted into a fluid connector 288, whereby to be simultaneouslyreleasably gripped, axially positioned and sealed. As shown, the fluidconnector 288 comprises a housing 290 having an annular shoulder 292leading into a stepped bore 294, an annular lock ring 296 and an annularO-ring 298 located in the bore 294, and a tubular unlock sleeve 300mounted to the shoulder. The lock ring 296 and the O-ring 298 aremounted in respective annular grooves formed in the stepped bore 294 andeach operates to radially engage the outer periphery of the conduit 284to inhibit its unwanted release. The lock ring 296 has a plurality ofradially inwardly directed spring tines 302 which are adapted to engagethe end portion 286 and lock the conduit 284 in the bore 294. The tines302 deflect radially outwardly upon engagement with the fluid conduit284 and direct the end portion 286 towards the O-ring 298 and the end285 of the conduit towards an endwall of the bore 294. The unlock sleeve300 includes a pair of axially spaced collars 304 and 306 which engageopposite axial faces of the annular shoulder 292, the collars beingaxially spaced to permit axial captivated movement of the unlock sleeve300 relative to the housing 290.

To effectuate release, the unlock sleeve 300 is forced axially inwardlyof the stepped bore 294 whereby the conical end face of the collar 306engages and drives the spring tines 302 radially outwardly. The collar304 prevents excess inward axial movement of the unlock sleeve 300 intothe stepped bore, such movement as could overstress the spring tines302, or possibly cause the collar 306 to be locked between the O-ring298 and the deflectable ends of the tines 302. In this regard, the wallbetween the annular groove receiving the lock ring 296 and the O-ring298 is tapered and serves to support the tines 302 during theirdeflection.

Referring to FIGS. 30-33, the improved spray gun 88 according to thisinvention is shown. The spray gun 88 includes a body 310 comprised of apolymeric or composite material which is preferably a glass-filled nylonwith a ceramic known as Esbrid, having a preferable Grade NSG440A orLSG440A with a color code of 70030 from Thermofil of Brighton, Mich.Specifically, the glass-filled nylon with a ceramic includes a mixtureof about 30% glass-filled nylon and about 70% ceramic material. Thiscomposite enables the body 310 to be formed from injection molding andhave a tensile strength of about 30,000 pounds. This provides animproved spray gun 88 which is both durable and light. For example, theimproved spray gun 88 weighs about 10 ounces versus about 22 ounces fora conventional spray gun made from aluminum. The body 310 includes ahandle portion 312, a head or baffle portion 314 and a neck portion 316.The neck portion 316 includes a curved hook 318 which may be used tohang the spray gun 88. The handle 312 defines a pair of cut-out regions320 located on opposite sides of the handle 312 which eliminateunnecessary material and ultimately reduces the overall weight of thespray gun 88. Cover plates (not shown) may be used to cover the cut-outregions 320 for aesthetic purposes and identification.

The head or baffle portion 314, which can be clearly seen in FIG. 33,includes an enlarged conical portion 322. The enlarged conical portion322 defines multiple enlarged air passages 324 to direct high pressureair out of the spray gun 88 for use in atomization of the paint, whichwill be discussed in detail shortly. Secured to the head 314 of thespray gun 88 is an air cap or spray atomizer 326 which is removably andsealably seated relative to the head 314, via a air cap retaining ring328 and an air baffle (not shown). The air cap 326 and the air capretaining ring 328 are preferably constructed of a polymeric material,such as Delrin and the air baffle is constructed of aluminum which isfixedly mounted to the head 314. Moreover, the air cap 326, theretaining ring 328 and the air baffle have a conventional configurationas is known to those skilled in the art.

In order for the air cap 326 to atomize the paint supplied by therecirculating liquid paint coating composition supply system 10, the aircap 326 includes a plurality of air holes 330 located about a fluid tip332 and within air horns 334. The air holes 330 direct high pressure airwhich is supplied to the gun 88, via a threaded air connection inletconnector 336, to control the spray pattern of the paint usingconventional techniques known in the art. The compressed air has apressure of about 70-100 psi and is supplied from a conventionalcompressed air source with an air hose, (not shown) that is removablycoupled to the air connection inlet connector 336.

Referring to the cross-section view of the body 310 of the spray gun 88,the air is first supplied or directed to an enlarged cylindrical taperedair passage 338 having a threaded end 340 for receiving the airconnection inlet connector 336. The air passage 338 is defined by thehandle 312 and has an opening diameter 342 of about 0.392 inches whichtapers to an exit opening 344 of about 0.340 inches. In contrast,conventional spray guns typically utilize a non-tapered cylindrical airpassage having a diameter of about 0.25 inches. The larger tapered airpassage 338 thus allows more volume of air to pass through the spray gun88 which provides for better atomization at any pressure.

A valve chamber 346, defined by the handle 312, threadably secures aconventional air valve assembly 348, partially shown in FIG. 30, viathreads 350. Air is directed or passes from the air passage 338 into thevalve chamber 346 through the air valve assembly 348. The air valveassembly 348 within the chamber 346, is controlled, via an air valve352, connected to a trigger 354. The trigger 354 is preferablyconstructed of metal and is pivotably secured to the neck 316, via atrigger bearing and stud 356. Upon actuation of the air valve assembly348, via the trigger 354, air passes through the air valve assembly 348and into and through an adjacent chamber 358, via a cylindrical taperedpassage 360, having a center diameter of about 0.26 inches. The chamber358 also being defined by the handle 312.

A conventional fluid needle assembly 362, partially shown in FIG. 30, isthreadably secured within the chamber 358, via a threaded coupling nut364 and threads 366. The fluid needle assembly 362 always allows air topass through the chamber 358 and also controls the amount of movement ofthe trigger 354 upon axially rotating a fluid adjustment knob 368. Thecoupling nut 364 and the fluid adjustment knob 368 are preferablyconstructed of a polymeric material, such as Delrin. Upon axiallyrotating the fluid adjustment knob 368, adjustment of the fluid flow outof the fluid tip 332 is made. In another words, the fluid adjustmentknob 368 adjusts or controls the amount the trigger 354 travels.

The air flow from the chamber 358 continues through a taperedcylindrical passage 370 having a center diameter of about 0.28 inches.It should be noted that the tapered cylindrical passages 360 and 370 areconcentric with one another and essentially consists of a single taperedpassage 372 which has an opening diameter 374 of about 0.353 inches andan ending diameter 376 of about 0.250 inches. Once the passage 372 isformed, a plug 378 is used to seal the top portion of the passage 372.

The air from the passage 370 is directed to and enters a cylindricaltapered passage 380 of the neck 316 which threadably secures aconventional spreader adjustment valve or air adjustment needle (notshown). The air adjustment needle is connected to a threaded air flowknob 382. The threaded air flow knob 382 threadably engages a couplingnut 384 which is secured within threads 386. The spreader adjustmentvalve controls the spray pattern of the fluid out of the fluid tip 332by axially extending or retracting the air adjustment needle within thetapered passage 380 in order to control the flow of air out of the airholes in the air horns 334. The air adjustment needle, the coupling nut384 and the air flow knob 382 are also preferably constructed of apolymeric material, such as Delrin.

As the air passes downstream in the passage 380, it enters or isdirected to the head portion or baffle 314. Upon entering the headportion 314, the airflow is divided into the three enlarged passages324, shown clearly in FIGS. 32 and 33. The enlarged conical portion 322is substantially larger than conventional heads which are typicallyabout half the size of the conical portion 322. This enables the airpassages 324 to have an enlarged diameter of about 0.200 inches versus aconventional diameter of about 0.156 inches. This further enables agreater volume of air to pass through and out of the head 314 and intothe conventional air baffle (not shown), providing even greateratomization. From the air passages 324, the air circulates about anannular channel 382 prior to exiting through the baffle and air holes330 in the air cap 326.

The recirculating paint is supplied, via the recirculating conduit 86,which is coupled to a threaded connector 384, via the fluid fittingassembly 108. The connector 384 is threadably connected to the body 310by threads 386. Upon actuating the trigger 354, a fluid needle 388 whichseals the fluid tip 332 axially moves in and out to enable the paint topass from the recirculating conduit 86 through a chamber 390, defined bythe head 314, and out the fluid tip 332. Upon exiting the fluid tip 332,the combination of the paint with the directional air supplied about theair cap 326 creates and directs an elliptical spray pattern to theobject to be coated or painted. The construction of the fluid needle 388within the chamber 390 is of a conventional nature known to thoseskilled in the art.

By coupling the conduit 86 to the head 314, via the chamber 390, thisenables the spray gun 88 to be used with various distinct fluid coatingswithout the need to flush out the spray gun 88. In other words, thespray gun 88 can be quick disconnected at the fluid fitting assembly 108and coupled to a new conduit 86 in order to apply a new liquid coatingcomposition. For example, different color paints can simply be appliedusing only the single spray gun 88 because the paint exits the spray gun88 substantially where it enters the spray gun 88 (i.e. the chamber390). This is in contrast to certain other existing spray guns whichsupply the paint through the handle, thereby causing larger amounts ofpaint to remain in the spray gun at all times, thus requiring the spraygun to be flushed out before a different color paint can be applied. Forinstance, the spray gun 88 will retain less than 2 cubic centimeters ofpaint in the chamber 390, while a spray gun in which the paint issupplied through the handle will retain over 20 cubic centimeters ofpaint throughout the entire gun. Moreover, this inhibits the paintwithin the gun from being recirculated.

By providing a polymeric composite spray gun 88 having a substantiallyreduced weight versus conventional metal spray guns, operator fatigue isgreatly reduced while finish quality is greatly increased over time.Moreover, the use of the lighter more durable spray gun 88 furtherreduces the chance of an operator developing any medical ailments whichmay be developed by continuous and repetitive use of the heavier metalspray guns. Additionally, the use of larger flow passages 338 and 324,enables a higher volume of air to pass through the spray gun 88, therebyproviding better atomization of the paint, as well as improved finishquality.

While the above description constitutes the preferred embodiment of theinvention, it will be appreciated that the invention is susceptible tomodification, variation, and change without departing from the properscope or fair meaning of the accompanying claims.

What is claimed is:
 1. A fluid supply system having a conduit adapted tobe coupled in fluid communication between a fluid source and a spray gunfor supplying fluid from the fluid source to the spray gun, said systemcomprising: a quick disconnect fluid coupling assembly adapted to beattached to the spray gun, said quick disconnect fluid coupling assemblyincluding a quick disconnect stem and a quick disconnect connectionoperable to receive said quick disconnect stem; a swivel fluid connectoroperable to allow the spray gun to rotate relative to the conduit; afilter fluid connector including a filter element operable to filter thefluid passing through the conduit; and a restrictor fluid connectorhaving an adjustable flow restrictor to adjust the flow of fluid throughthe conduit; wherein at least one of said quick disconnect fluidcoupling assembly, said swivel fluid connector, said filter fluidconnector and said restrictor fluid connector is formed substantially ofa polymeric material to reduce the overall weight of the system.
 2. Thefluid supply system as defined in claim 1 wherein each of said quickdisconnect fluid coupling assembly, said swivel fluid connector, saidfilter fluid connector and said restrictor fluid connector are formedsubstantially of a polymeric material.
 3. The fluid supply system asdefined in claim 1 wherein said quick disconnect fluid coupling assemblyincludes a closure member retained in said quick disconnect connectionfor movement between a first position and a second position and operableto prevent and permit the fluid to pass through said quick disconnectconnection.
 4. The fluid supply system as defined in claim 3 whereinsaid quick disconnect connection includes a seal mounted in a borepassing through said quick disconnect connection operable to assist insealing said quick disconnect connection, said seal having a first endface opposite a second end face and a fluid passage extending betweensaid end faces, said second end face forming an inwardly tapered skirt,said closure member mounted in said fluid passage and being biased intosealing engagement with said first end face and in covering relationwith said fluid passage.
 5. The fluid supply system as defined in claim1 wherein said swivel fluid connector includes a body having a boreextending between forward and rearward portions and a rotatably couplingnut on said forward portion to couple to said quick disconnect fluidcoupling assembly.
 6. The fluid supply system as defined in claim 1wherein said filter fluid connector includes first and second ferrulesand said filter element is captured between said first and secondferrules.
 7. The fluid supply system as defined in claim 1 wherein saidrestrictor fluid connector includes a centrally bored fluid housing anda coupling nut mounted to a forward end portion of said housing operableto attach to said filter fluid connector.
 8. The fluid supply system asdefined in claim 1 wherein said restrictor fluid connector includes aninput port and a return port that flow from a central fluid passage. 9.The fluid supply system as defined in claim 1 wherein at least one ofsaid quick disconnect fluid coupling assembly, said swivel fluidconnector, said filter fluid connector, and said restrictor fluidconnector is substantially formed from a glass filled nylon.
 10. Thepaint supply system as defined in claim 9 wherein said glass fillednylon further includes a ceramic.
 11. A fluid supply system having aconduit adapted to be coupled in fluid communication between a fluidsource and a spray gun for supplying fluid from the fluid source to thespray gun, said system comprising: a swivel fluid connector operable toallow the spray gun to rotate relative to the conduit; a filter fluidconnector including a filter element operable to filter the fluidpassing through the conduit; and a restrictor fluid connector having anadjustable flow restrictor to adjust the flow of fluid through theconduit; wherein at least one of said swivel fluid connector, saidfilter fluid connector and said restrictor fluid connector is formedsubstantially of a polymeric material to reduce the overall weight ofthe system.
 12. The fluid supply system as defined in claim 11 wherein aquick disconnect fluid coupling assembly is adapted to be attached tothe spray gun, said quick disconnect fluid coupling assembly including aquick disconnect stem and a quick disconnect connection operable toreceive said quick disconnect stem.
 13. The fluid supply system asdefined in claim 12 wherein said quick disconnect connection includes afirst fluid bore extending therethrough, said quick disconnectconnection including a first closure member movably positioned between afirst position and a second position in said first fluid bore forpreventing and permitting fluid to pass through said first fluid bore,and said quick disconnect stem includes a second fluid bore extendingtherethrough, said quick disconnect stem including a second closuremember movably positioned between a third position and fourth positionin said second fluid bore for preventing and permitting fluid to passthrough said second fluid bore, wherein upon connecting said quickdisconnect connection with said quick disconnect stem, said firstclosure member is moved to said second position and said second closuremember is moved to said fourth position to permit fluid to pass throughsaid first and second fluid bores.
 14. The fluid supply system asdefined in claim 11 wherein each of said swivel fluid connector, saidfilter fluid connector and said restrictor fluid connector are formedsubstantially of a polymeric material.
 15. A fluid supply system havinga conduit adapted to be coupled in fluid communication between a fluidsource and a spray gun for supplying fluid from the fluid source to thespray gun, said system comprising: a swivel fluid connector operable toallow the spray gun to rotate relative to the conduit; a filter fluidconnector including a filter element operable to filter the fluidpassing through the conduit; and a restrictor fluid connector having anadjustable flow restrictor to adjust the flow of fluid through theconduit; wherein each of said swivel fluid connector, said filter fluidconnector and said restrictor fluid connector are formed substantiallyof a polymeric material to reduce the overall weight of the system. 16.The fluid supply system as defined in claim 15 wherein a quickdisconnect fluid coupling assembly is adapted to be attached to thespray gun, said quick disconnect fluid coupling assembly including aquick disconnect stem and a quick disconnect connection operable toreceive said quick disconnect stem.
 17. The fluid supply system asdefined in claim 16 wherein said quick disconnect connection includes afirst fluid bore extending therethrough, said quick disconnectconnection including a first closure member movably positioned between afirst position and a second position in said first fluid bore forpreventing and permitting fluid to pass through said first fluid bore,and said quick disconnect stem includes a second fluid bore extendingtherethrough, said quick disconnect stem including a second closuremember movably positioned between a third position and fourth positionin said second fluid bore for preventing and permitting fluid to passthrough said second fluid bore, wherein upon connecting said quickdisconnect connection with said quick disconnect stem, said firstclosure member is moved to said second position and said second closuremember is moved to said fourth position to permit fluid to pass throughsaid first and second fluid bores.
 18. The fluid supply system asdefined in claim 15 wherein each of said swivel fluid connector, saidfilter fluid connector and said restrictor fluid connector aresubstantially formed from a glass filled nylon.